Section liner drawing instrument - GIF

[Altair]

A section liner is a drawing instrument used for drawing parallel lines.




Previously:

Constrained ball line drawing aid - photo
Rastrum multi-nib pen - photo
Drawing a perfect circle on a chalkboard - GIF
Drawing three right angles on a sphere - GIF

[mklotz]

Rolling rulers are still sold...

https://www.amazon.com/MyLifeUNIT-Mu...s%2C207&sr=8-3

and, IMO, are easier to use and require less work space than conventional parallel rulers...

https://www.amazon.com/Alvin-A1500-1...s%2C207&sr=8-1

[Toolmaker51]

Still using both rolling and walking parallels, a lot to enjoy about mechanical drawing.
This rack and pinion thing is new to me, and maybe as old, but that HB lead makes worst section lines ever!